Track topics on Twitter Track topics that are important to you
This research study involves the use of the drugs Letrozole, GnRH, and NAL-GLU GnRH antagonist. Letrozole is a drug that is approved by the U.S. Food and Drug Administration (FDA) for use in breast cancer treatment that has been found to block the formation of estrogen. The NAL-GLU GnRH antagonist is a drug that temporarily blocks the action of GnRH. GnRH is a hormone that the body makes that stimulates other hormones that then control the function of the ovary.
The purpose is to study the effects of the administration of letrozole in women with GnRH deficiency at the same time that they receive gonadotropin-releasing hormone (GnRH). In addition, administration of letrozole and NAL-GLU GnRH antagonist in healthy women with normal menstrual cycles will be done to evaluate the role of estrogen in the control of the hormone FSH, or Follicle Stimulating Hormone, in the female reproductive cycle. A better understanding of FSH control may help in the development of new treatments for women with difficulty conceiving.
The negative feedback control of FSH is crucial for the precise regulation of follicular development in the female. An important component of this feedback is exerted by estrogen. Letrozole will be used to block aromatase and therefore estradiol production in normal and GnRH deficient females. These studies will dissect the relative roles of estradiol and inhibin on FSH secretion at the pituitary and hypothalamus.
The aromatase inhibitors block aromatization of androgens to estrogens, allowing us to examine the relative contribution of estradiol and inhibin to FSH regulation. Using normal subjects and GnRH-deficient subjects receiving replacement GnRH allows us to compare the effect of relative estradiol blockade at the pituitary (GnRH deficient subjects) vs the pituitary and hypothalamus (normal subjects), thus determining the direct site of estradiol action.
A more thorough understanding of estrogen and inhibin feedback on FSH will improve our understanding of the failure of follicle development in subsets of patients with infertility, such as polycystic ovary syndrome, in which FSH levels are normal but follicles fail to develop. Study of FSH control will also help us understand the failure of negative feedback on FSH, which can result in multiple follicular development and multiple gestation and its associated costs and risks. Thus, these studies may afford new therapeutic options for conception in infertile patients while simultaneously providing new methods to avoid the risks of multiple gestations.
Allocation: Non-Randomized, Control: Active Control, Intervention Model: Parallel Assignment, Masking: Open Label
Letrozole, NAL-GLU GnRH antagonist, GnRH
Reproductive Endocrine Unit, Massachusetts General Hospital
Massachusetts General Hospital
Published on BioPortfolio: 2014-08-27T03:43:34-0400
Failure to respond to controlled ovarian hyperstimulation (COH) is still a major concern in assisted reproduction and there is no consensus on the ovarian stimulation ...
The purpose of this study is to compare pregnancy rates and the occurrence of OHSS in PCOS patients who were treated with GnRH agonist and GnRH antagonist protocols ovarian stimulation dur...
The purpose of the study is to examine how Kallmann syndrome (KS) and idiopathic hypogonadotropic hypogonadism (IHH) affect reproductive hormones. These disorders are caused by a defect in...
This prospective and randomized study was performed to evaluate whether the replacement of GnRH agonist by a GnRH antagonist in oocyte donation recipients during endometrial preparation h...
Men with Idiopathic Hypogonadotropic Hypogonadism (IHH) lack a hormone called gonadotropin releasing hormone (GnRH). This hormone is important for starting puberty, maintaining testosteron...
The concept that the positive feedback effect of ovarian estradiol (E) results in GnRH and gonadotropin surges is a well-established principle. However, a series of studies investigating the rapid act...
This study aimed to evaluate the effect of three days of GnRH antagonist pretreatment on the pregnancy outcomes of women with polycystic ovarian syndrome (PCOS) on GnRH antagonist protocols for IVF/IC...
Gonadotropin-releasing hormone (GnRH) secretion from GnRH neurons and its modulation by neuropeptides are essential for mammalian reproduction. Here, I review the neuropeptides that have been shown to...
Poor ovarian response (POR) to ovarian hyperstimulation is one of the biggest challenges in assisted reproduction technology. The objective of this study was to compare the efficacy of progestin-prime...
Is allograft inflammatory factor-1 (AIF-1), a cytokine associated with inflammation and allograft rejection, aberrantly elevated in in vitro fertilization (IVF) cycles with gonadotropin-releasing horm...
A genetically heterogeneous disorder caused by hypothalamic GNRH deficiency and OLFACTORY NERVE defects. It is characterized by congenital HYPOGONADOTROPIC HYPOGONADISM and ANOSMIA, possibly with additional midline defects. It can be transmitted as an X-linked (GENETIC DISEASES, X-LINKED), an autosomal dominant, or an autosomal recessive trait.
A decapeptide that stimulates the synthesis and secretion of both pituitary gonadotropins, LUTEINIZING HORMONE and FOLLICLE STIMULATING HORMONE. GnRH is produced by neurons in the septum PREOPTIC AREA of the HYPOTHALAMUS and released into the pituitary portal blood, leading to stimulation of GONADOTROPHS in the ANTERIOR PITUITARY GLAND.
Receptors with a 6-kDa protein on the surfaces of cells that secrete LUTEINIZING HORMONE or FOLLICLE STIMULATING HORMONE, usually in the adenohypophysis. LUTEINIZING HORMONE-RELEASING HORMONE binds to these receptors, is endocytosed with the receptor and, in the cell, triggers the release of LUTEINIZING HORMONE or FOLLICLE STIMULATING HORMONE by the cell. These receptors are also found in rat gonads. INHIBINS prevent the binding of GnRH to its receptors.
A progestational and glucocorticoid hormone antagonist. Its inhibition of progesterone induces bleeding during the luteal phase and in early pregnancy by releasing endogenous prostaglandins from the endometrium or decidua. As a glucocorticoid receptor antagonist, the drug has been used to treat hypercortisolism in patients with nonpituitary CUSHING SYNDROME.
A thiazole derivative and atypical ANTIPSYCHOTIC AGENT that functions as a DOPAMINE D2 RECEPTOR ANTAGONIST; SEROTONIN 5-HT2 RECEPTOR ANTAGONIST, serotonin 5-HT7 receptor antagonist, and antagonist of the adrenergic α2A and α2C receptors, as well as a partial SEROTONIN 5-HT1A RECEPTOR AGONIST. It is used in the treatment of SCHIZOPHRENIA and BIPOLAR DISORDER.
Pharmacy is the science and technique of preparing as well as dispensing drugs and medicines. It is a health profession that links health sciences with chemical sciences and aims to ensure the safe and effective use of pharmaceutical drugs. The scope of...
Women's Health - key topics include breast cancer, pregnancy, menopause, stroke Follow and track Women's Health News on BioPortfolio: Women's Health News RSS Women'...